Read the run-on sentence.
Justin rushed through the obstacle course he couldn't make it over the final obstacle in time.
What is the best way to revise the sentence?
Justin rushed through the obstacle course, but he couldn't make it over the final obstacle in time.
Justin rushed through the obstacle course couldn't make it over the final obstacle in time.
Justin rushed through the obstacle course, he couldn't make it over the final obstacle in time.
Justin rushed through the obstacle course; but he couldn't make it over the final obstacle in time.